Congestive heart failure (CHF or HF) is a major health problem and affects many people in the United States alone. CHF patients can have enlarged heart with weakened cardiac muscles, resulting in poor cardiac output of blood. Although CHF is usually a chronic condition, it can occur suddenly. It can affect the left heart, right heart or both sides of the heart. If CHF affects the left ventricle, signals that control the left ventricular contraction are delayed, and the left and right ventricles do not contract simultaneously. Non-simultaneous contractions of the left and right ventricles further decrease the pumping efficiency of the heart.
In many CHF patients, elevated pulmonary vascular pressures can cause fluid accumulation in the lungs over time. The fluid accumulation can precede or coincide with worsening HF such as episodes of HF decompensation. The HF decompensation can be characterized by pulmonary or peripheral edema, reduced cardiac output, and symptoms such as fatigue, shortness of breath, and the like.